Moons of Pluto

Moons on Pluto
Name Mean diameter (km) Mass (×1021 kg) Semi-major
axis (km)
Orbital period (days) Discovery date
Pluto 2390 13.05 ± 0.07 2 035* 6.387 230 1930
Pluto I   Charon 1207 ± 3 1.52 ± 0.06 17 536 ± 3* 6.387 230 1978
Pluto II Nix 46-137 < 0.002 48 708 24.856 ± 0.001 2005
Pluto III Hydra 61-167 < 0.002   64 749 38.206 ± 0.001 2005